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BTRFS-QGROUP(8) | Btrfs Manual | BTRFS-QGROUP(8) |
NAME¶
btrfs-qgroup - control the quota group of a btrfs filesystemSYNOPSIS¶
btrfs qgroup <subcommand> <args>DESCRIPTION¶
btrfs qgroup is used to control quota group (qgroup) of a btrfs filesystem.QGROUP¶
Quota groups or qgroup in btrfs make a tree hierarchy, the leaf qgroups are attached to subvolumes. The size limits are set per qgroup and apply when any limit is reached in tree that contains a given subvolume. The limits are separated between shared and exclusive and reflect the extent ownership. For example a fresh snapshot shares almost all the blocks with the original subvolume, new writes to either subvolume will raise towards the exclusive limit. The qgroup identifiers conform to level/id where level 0 is reserved to the qgroups associated with subvolumes. Such qgroups are created automatically. The qgroup hierarchy is built by commands create and assign.SUBCOMMAND¶
assign [options] <src> <dst> <path>Assign qgroup <src> as the child qgroup of
<dst> in the btrfs filesystem identified by <path>.
Options
--rescan
create <qgroupid> <path>
Automatically schedule quota rescan if the new qgroup
assignment leads to quota inconsistency.
--no-rescan
Explicitly ask not to do a rescan.
Create a subvolume quota group.
For the 0/<subvolume id> qgroup, a qgroup can be
created even before the subvolume created.
destroy <qgroupid> <path>
Destroy a qgroup.
If a qgroup is no isolated,which means it is a parent or child qgroup, it
can’t be destroyed.
limit [options] <size>|none [<qgroupid>]
<path>
Limit the size of a qgroup to <size> or no
limit in the btrfs filesystem identified by <path>.
If <qgroupid> is not given, qgroup of the subvolume identified by
<path> is used if possible.
Options
-c
remove <src> <dst> <path>
limit amount of data after compression. This is the
default, it is currently not possible to turn off this option.
-e
limit space exclusively assigned to this qgroup.
Remove the relationship between child qgroup
<src> and parent qgroup <dst> in the btrfs
filesystem identified by <path>.
show [options] <path>
Show all qgroups in the btrfs filesystem identified by
<path>.
Options
-p
print parent qgroup id.
-c
print child qgroup id.
-r
print limit of referenced size of qgroup.
-e
print limit of exclusive size of qgroup.
-F
list all qgroups which impact the given path(include
ancestral qgroups)
-f
list all qgroups which impact the given path(exclude
ancestral qgroups)
--raw
raw numbers in bytes, without the B suffix.
--human-readable
print human friendly numbers, base 1024, this is the
default
--iec
select the 1024 base for the following options, according
to the IEC standard.
--si
select the 1000 base for the following options, according
to the SI standard.
--kbytes
show sizes in KiB, or kB with --si.
--mbytes
show sizes in MiB, or MB with --si.
--gbytes
show sizes in GiB, or GB with --si.
--tbytes
show sizes in TiB, or TB with --si.
--sort=[+/-] <attr>[,[+/-]<attr>]...
list qgroups in order of <attr>.
<attr> can be one or more of qgroupid,rfer,excl,max_rfer,max_excl.
Prefix '+' means ascending order and '-' means descending order of
<attr>. If no prefix is given, use ascending order by default.
If multiple <attr>s is given, use comma to separate.
EXIT STATUS¶
btrfs qgroup returns a zero exit status if it succeeds. Non zero is returned in case of failure.AVAILABILITY¶
btrfs is part of btrfs-progs. Please refer to the btrfs wiki http://btrfs.wiki.kernel.org for further details.SEE ALSO¶
mkfs.btrfs(8), btrfs-subvolume(8), btrfs-quota(8),10/02/2016 | Btrfs v4.7.3 |